1. Field of the Invention
The present invention relates to a waterproof plug for a connector and a waterproof connector comprising the same, in more particular, to a waterproof plug for a connector for sealing a housing which houses a terminal, a waterproof connector comprising the same and a method of attaching the same.
2. Related Art
There is a conventional waterproof connector comprising a terminal fixed at an edge of an electric cable, a housing for housing this terminal in the inside thereof, a seal member as a waterproof plug for sealing (liquid seal) this housing and a holder for holding the electric cable by positioning the seal member inside the housing (for example, disclosed by JP-A 2005-129460).
The terminal has a projection (a stabilizer) for preventing a reverse insertion and is locked inside the housing.
The housing has a locking portion for locking the terminal and a guide for guiding the stabilizer, and is configured to open on a cable insertion side and an external terminal connection side for housing a portion of the electric cable, the seal member and the holder with the terminal in the inside thereof.
The seal member has a through hole allowing the press-fitting of the terminal and the electric cable, is housed in a state of being pressed against the inside of the housing and is entirely formed of a soft elastic material such as, for example, rubber or the like.
The holder has a through hole letting through the electric cable and is mounted inside the housing. And it is configured to be positioned at a predetermined position by pressing the seal member from the cable insertion side to the external terminal connection side when inserting the holder into the housing.
From the above-mentioned configuration, the waterproof connector is attached by inserting the seal member into the housing from the opening on the cable insertion side so as to be placed at a predetermined position, sequentially placing the holder on the cable insertion side of the seal member, subsequently passing the electric cable through by inserting the terminal into a through hole of the holder and that of the seal member, and pressing the seal member in a thickness direction thereof by moving the holder from the cable insertion side to the external terminal connection side after locking the terminal to the locking portion inside the housing.
In this case, when the seal member receives pressure from the holder, the seal member is compressed in the thickness direction thereof and expands in a direction to press against an inner surface of the housing, thereby sealing the opening of the housing (an opening on the cable insertion side).
However, according to the conventional waterproof connector, there is a possibility that sealing performance deteriorates as the seal member is damaged by the stabilizer of the terminal which scratches an inner periphery of the through hole of the seal member when passing the electric cable through the through hole of the sealing member.